Adjustable dental tray



E. A. CLEVELAND ADJUSTABLE DENTAL TRAYv Apri? l 1924.

Filed Jan. 29. 1925 .patented ipr. l, i924..

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nnnns'r a. CLEVELAND, or normanni., annesso, canapa. I

AEJUSTAIBLE DENTAL TMY.

Application filed January fw, 1923. Serial No. 615,718.

To all whom vz'zf may concern:

Be it known that l, ERNEST A. CLEVELAND, a subject of the King of Great Britain, residing at Montreal, Province of Quebec, Canada, have invented certain new and useful Improvements in Adjustable- Dental Trays; and l do hereby declare that the following.,lr is a full, clear, and exact description ci the invention, such as will ena-ble others skilled in the artto which it appert-ains to make and use the same.

The present invention rela-tes to novel improvements in dental trays used by den-l tists for taking impressions of the teeth.

A device of this character of the type now in use consists-0f a tray or other suitable receptacle adapted to contain a quantity oit plaster which is pressed against the teeth for taking an impression thereof. Subsequently .a model is made from the impression and an artificial set of teeth constructed in accordance'with this model. ln the use of such devices it has heretofore been difficult to remove the tray and plaster from the mouth without injury to the patient due to the plaster l'iardening against the teeth. To overcome this defect a modeling compound, which is a yieldable substance, has been introduced, but this is objectionable in that the impression is altered while the cast is being drawn away from the teeth. The present invention aims to overcome the didiculty in removing the cast from the teeth, at the same time maintaining the accuracy of the impression. The cast before removal from the teeth has a tendency to crack medially vin a curved plane between the front .Y and back wall `ot Ithe impression. ln the improved tray, this tendency is allowed to manifest itself in that the outer surface of the tray may be moved, thus increasing the width of the space within the cup, while the tray is still in the mouth. When the tray is withdrawn, the parts of the cast on opposite sides of the crack are allowed to seperate, whereby they may be removed from the teeth without alteration of the true impression. To avoid the plaster adhering to `the teeth during the removal of the tray, the walls ot the latter are undercut or provided with flanges at the outer edges so that the plaster is gripped and carried with the tray. 1

rl`he invention' is fully disclosed in the view showing the vFigure 4 is a section on the line 4 4 of F i ure 3.

s illustrated in these views in which like .reference characters are employed to designate corresponding parts throughout, the tray comprises a handle 1 which is formed integrally with or. secured to a hase 2 having the general curvature of a set of teeth. At the inner edge of the base is formed an ups/sanding; wall 3 which constitutes the lingual portion. The outer Wall is formed in two sections 4 each 'of which carries a flange 5 at its lower ed e. The branches of the biise are formed att .e under surface with enlargements 5 in which. are cut dovetail grooves 6 adapted to receive the flanges 5 in slidable manner. The sidewall sections 4. when attached to the base by means ot the flanges and grooves stand parallel to the inner Wall 3 forming the space 7 for recciving the material in which the impression is taken. rlhe upper edges of the walls 3 and l are undercut or formed with flanges 8 and 9 respectively projecting into the space 7,

In use, the cup is inserted into the mouth after receiving a quantity ci plaster, and is pushed against the set of teeth of which the impression is to be taken. After the plaster has remained in contact with the teeth for the required period of time, the wall sections 4i are moved outwardly to allow the cast to crack in the manner pointed out above. The tray is now moved away from the teeth with case and without distortion of the impression since the separated portions of the cast are allowed to move apart. As the tray is moved away from the teeth, the cast isprevented `from adhering thereto by virtue of the flanges 8 and 9 which pull it in the direc tion in which the tray is drawn. After removal from the mouth, the wall sections 4: are returned to their original positions, and the run is made. After the latter has hardcned, the wall sections are removed entirely, the cast still remaining in engagement with esl the lingual porlion. The tray turned 5o that he handle points upwardly, the 'env enil. of the handle is tapped Wit-h the other henri, where-liv the i'irey is; sepereerl :from 'die and drops ewey from il.

The device is applicable lo either oi' leeh. The sliilnhility of Sho wall secieue ie further useful. in, azljusing rho trey to various sizes of niouhe.

"While e epeeiiie embodiment of the invention has been illustrated, and des/exileeil.- il, ie te be iunlere'lool the?. various elnerw tiene in lle details ol' eonsruetion muy he mede Without departing from the spirit. of the invention es indicated; by he appended claims. y

Having 'linie fully described he invention, what claim es new and desire to protect e); .Patent iszl.' il. denial tray comprising a hase having subs'izen'lielly the curvature of a coxnplete'set of teeth, en inner Wall the inner edge of seid bese and substantially perpendicular thereto, end e pen o outer well sections ai'. the outer edge and Slideole relneively io seid inner well.

L dental trov eonnirieing o onse having Subs o"I veel i, an inner well at the inner edge oi Seid bese and substantially perpendicular hereio, enel outer Well seeions at the outer edge end sldehly conneeed to ehe bese.

dental rey eoinprieing e beseheving rees.

*eentiellv lhe curvenre of e complete :sely

.nilislrn'iully the curvature of a coniplete'set li) en inner wall et the inner edge of aid heee, e pair of outer Wall sections at the outer erige and sliclabie relatively to said inner will, and flanges eizencling from the 40 upper of seid inner wall and vouter wall. sections info the space therebetween.

i denial tray comprising a base having eubelentielly lire curvature of a complete set ol teeth, an inner welll at the inner edge of Seid heee. oulier wall sections at the outer and siiilelely connected to the base, and le-nues extending from the upper edges of inner will and outer Wall sections into he space therebeween.

5. A. denial rey comprising obese having substantially the clilrveure ol' a complete set of feeeth, an inner will el; the inner edge of seid hase, seid bese having grooves formed in .its eurfeee, end outer well sections provided with flanges elidebly receivable in Said grooves.

(i, A dental tray comprising abase having subslzentielly "the curvature of e complete set, of reelln en inner woll at the inner edge of seid bese, seid base having grooves formed in ite surfece, outer well sections provided wih lienges slidably receivable in said grooves, enel flanges extending from the upper edges el seidv inner Well and outer Wall sections into the space nhereloetween.

En witness whereof Il have hereunto set my hand.

ERNEST A. CLEVELAND. 

